4 days ago
How QR Codes Power Everyday UPI Payments in Seconds
A QR code is a small square that stores information using black and white blocks.
When you scan it, your phone first finds the code and understands which way it is facing.
It then turns the blocks into digital information.
For a payment, that information can identify the seller and sometimes the amount.
Your payment app shows these details so you can check them.
You approve the payment by entering your UPI PIN.
The QR code does not hold or move your money.
UPI uses the decoded details to transfer money from your bank account to the seller’s account.
QR codes store machine-readable payment details such as a merchant’s UPI ID, name, reference number and sometimes the amount.
Finder patterns help a phone locate, orient and decode a QR code from different angles.
Static QRs usually require customers to enter the payment amount, while dynamic QRs can include transaction-specific amounts and references.
Reed-Solomon error correction allows many QR codes to remain readable despite dirt, scratches or partial damage.
The QR code provides payment instructions, while UPI transfers money between participating banks and payment-service providers.
- Who
- QR codes, smartphones, UPI payment apps, participating banks and payment-service providers.
- What
- QR codes encode payment instructions that help initiate UPI transactions.
- Where
- They are used at places including ice-cream carts, vegetable stalls, chai stalls, kirana shops, restaurants and digital checkout pages.
- When
- QR codes were invented in Japan in 1994; a UPI scan and payment can be completed within seconds.
- Why
- They allow payment apps to quickly identify the payee and, in some cases, the amount to be paid.
Key facts
- QR meaning
- QR stands for Quick Response.
- Invention
- Engineer Masahiro Hara invented the QR code in Japan in 1994.
- Original purpose
- QR codes were originally created to track car parts in factories.
- Code size
- QR codes can range from 21 × 21 to 177 × 177 modules.
- Static QR
- A static QR keeps the merchant’s payment details embedded in the code, with the customer generally entering the amount.
- Dynamic QR
- A dynamic QR can include transaction-specific details such as the amount and transaction reference.
- Error correction
- QR codes use Reed-Solomon error correction, with four correction levels.









